Magnetically recoverable N-containing Fe–Mn/carbon catalyst for peroxydisulfate activation and bisphenol A degradation via a predominantly surface-associated nonradical pathway

A magnetically recoverable N-containing Fe–Mn/carbon catalyst was prepared from terephthalic acid, p-phenylenediamine, FeCl 3 ·6H 2 O, and MnCl 2 ·4H 2 O through a coordination–calcination route. The best-performing formulation was obtained at an Fe/Mn precursor mass ratio of 1:1, a p-PDA/TPA mass ratio of 0.05, and 550°C calcination. Characterization indicated a multiphase Fe–Mn oxide/carbon architecture with retained nitrogen, mesoporous characteristics, hierarchical morphology, and magnetic responsiveness. Under the selected conditions of 20 mg L −1 BPA, 1.5 g L −1 catalyst, 0.7 g L −1 PDS, and initial pH 7, BPA removal reached 97.63% within 30 min. High degradation performance was maintained over initial pH 3–7. Methanol caused little inhibition, tert-butanol produced a moderate effect, whereas sodium azide strongly suppressed BPA degradation. The system exhibited high matrix resilience against coexisting anions (Cl − , NO 3 − , HCO 3 − , SO 4 2− ), humic acid, and authentic municipal wastewater (94.63% removal). Together with the scavenging response, these results support a predominantly surface-associated nonradical pathway with an important singlet-oxygen-associated contribution. The catalyst retained 80.98% BPA removal after five consecutive cycles and could be magnetically recovered. Overall, the Fe–Mn/N-containing carbon architecture provides an effective and reusable heterogeneous PDS activator for rapid BPA degradation under neutral conditions without external irradiation or heating.